Kai Wong, M.S.
Education: Bachelor of Science in electrical engineering (December 2003)
Master of Science in electrical engineering from Kansas State University
McNair Project: Simulating Bluetooth Networks Using OPNET (2002)
Mentor: Don Gruenbacher, Ph.D.
In recent years, consumers have developed a growing interest in wireless electronic devices, such as personal digital assistants, cell phones, wireless laptop computers, and other portable devices. Each of these devices only meets part of our needs, so we need to develop a networking interface to interconnect them. Bluetooth is on target to fulfill such a need, and it is rising as an essential standard for short range, low-power wireless communication. Bluetooth is ideal for the wireless task because of its low power consumption, its flexibility to allow devices to talk spontaneously and its mobility that allows users to move from the range of one access point to another. This paper provides insights into issues related to internetworking such as arranging small groups of "piconets" to form a larger "scatternet", within the constraints imposed by the Bluetooth Specifications. The paper then introduces the simulation software called Opnet to build the piconet and scatternet models. Opnet is a simulation environment that has high-reliability and discrete-event models. It allows the user to predict performance characteristics and study behavioral interaction for personal area network (PAN) applications that use both on existing and emerging wireless technologies. This paper presents the models and the analysis of the simulation results produced by Opnet. It also evaluates the properties within the networks that lead to good performance in terms of end-to-end delay and link utilization for both piconets and scatternets.
McNair Project: Microwave Network Analyzer Measurement with LabVIEW of Spiral Inductors (2003)
Mentor: William Kuhn, Ph.D.
In today's high technology market, manufacturers are looking to build better products for wireless applications such as mobile phones, pagers and cordless equipment. Testing of these high frequency components requires a Microwave Network Analyzer, which costs around $45,000 or more -- a major obstacle for many microwave circuit researchers and designers at engineering colleges. This paper provides a way to own a similar set of instruments with about one tenth of the funding.
A LabVIEW program can perform SOL calibrations and acquire/display the reflection coefficients of the device under test on the computer screen in a Smith chart. With the addition of a LabVIEW program to our older Hewlett-Packard network analyzer set, calibration correction factors can be applied, accomplish the same task as today's one-piece system, but at very low cost.
Comparing the SOL standards re-measured after completing the calibration results to our theoretical results of the SOL standards, this paper shows, they were well matched. Comparing the measurements taken with the reference plane modified using the 8743B line-stretcher to our theoretical values, we concluded that our LabVIEW program is working accurately with our network analyzer set. For economic reasons, the tradeoff of our system is taking more time than the modern machine to calibrate the network analyzer and collect the data points is acceptable. Since our project LabVIEW VI only applies to One Port calibration, further enhancement is needed to make it available for Two Ports, to make a complete "microprocessor-equipped" Microwave Network Analyzer set. Source code has been published on the Internet to allow others to both use our existing product and extend it to 2-port measurements if desired.